Air flotation separator



Sept. 29, 1970 A R. A. KIPP AIR FLOTATION SEP ARATOR 3 Sheets-Sheet lFiled July 29, 1968 FIG. 2

I N VENTOR. BY fiMEmZ/Q ZIP/ [m 6 @j sa Sept. 29, 1970 R. A. KIPP AIRFLOTATION SEPARATOR 3 Sheets-Sheet 2 Filed July 29, 1968 nvmmmmmmmmw067.fi. 6 0 1 My M ATTORNEY United States Patent Office 3,530,987Patented Sept. 29, 1970 3,530,987 AIR FLOTATION SEPARATOR Robert A.Kipp, 8 Fulham Ave., Winnipeg 9, Manitoba, Canada Continuation-impart ofapplication Ser. No. 712,054, Mar. 11, 1968. This application July 29,1968, Ser. No. 748,520

Int. Cl. B03b 3/12, 3/34 US. Cl. 209-467 19 Claims ABSTRACT OF THEDISCLOSURE An air flotation machine having a shaker frame suspended by aflexible rubber web or the like with a removable screen assembly beingheld in the frame by upward spring pressure and having the discharge endof the screen assembly adjustable in inclination within limits tocontrol the contaminant discharge characteristics.

The invention relates to improvement in air flotation stoner machines ofthe type which incorporates an oscillating or vibrating screen situatedon an incline and constitutes a continuation-in-part to Ser. No.712,054, filed Mar. 11, 1968 and now abandoned. The material to becleaned such as grain or the like, is fed onto the upper side of thescreen and this material is fluidized by the passage of air through thescreen and material either by blowing from the underside thereof or bysuction upon the upper side thereof or a combination of both. Thiscauses the bed of material to fluidize and move downwardly to bedischarged at the lower end. Contaminants having the highest specificgavity such as stones, nails or the like, remain in contact with thescreen and are not fluidized by the airflow. The vibration of the screencauses these contaminants to move upwardly against the downward flow ofmaterial whereupon they are collected within a narrow throat anddischarged over the end thereof.

The improvements consist firstly of a shaker screen construction whichis easily removed'from the machine for cleaning or repair purposes. Thisis accomplished by suspending the shaker screen assembly by a rubber orsimilar resilient material web which not only supports the screen foreasy removal, but also causes the area above the screen to be sealedthus facilitating the air flow therethrough.

Secondly, it will be appreciated that the characteristics of themachines operation will be varied by the degree of slope of the screenand this usually has been accomplished by tilting the entire machine.

The improvement herein described permits the screen to be at a fixedslope, it being the throated contaminant discharge end which is readilyadjustable as required and while the machine is operating in order tomaintain the efficient separation of the contaminants and the materialbeing cleaned.

T hirdly, the construction of the screen utilizes a honeycomb corecovered on the upper side by a plastic o nylon mesh screen.

It is desirable to be able to control the amount of air passing througheach cell of the honeycomb in order that the fluidized bed of theproduct be maintained.

This is accomplished in the present application by attaching sheets orstrips of perforated paper over the underside of the honeycomb, therebeing a perforation for each cell of the honeycomb. By varying thestrips and sizes or numbers of perforations, infinite control of the theair fiow passing through the honeycomb is achieved.

With the foregoing considerations in view, and such other objects,purposes or advantages as may become apparent from consideration of thisdisclosure and specification, the present invention consist of theinventive concept exhibited in the method, process, construction,arrangement of parts, or new use of any of the foregoing hereinparticularly exemplified in one or more specific embodiments of suchconcept, reference being had to the accompanying figures in which:

FIG. 1 is a top plan view of the machine.

FIG. 2 is an enlarged side elevation thereof fragmented to show theinterior thereof.

FIG. 3 is a top plan view of the machine with the upper cover removedfor clarity.

FIG. 4 is an enlarged fragmentary sectional view substantially along theline 4-4 of FIG. 3 and showing the mounting of the shaker frame.

FIG. 5 is an enlarged fragmentary view showing the details of one of theplunger assemblies.

FIG. 6 is an enlarged fragmentary View showing the control for theplunger assemblies.

FIG. 7 is a top plan view of the screen assembly fragmented in part toshow the interior thereof.

FIG. 8 is a partial section of the screen of FIG. 7 enlarged forclarity.

FIG. 9 is an end view of the lower half of the machine showing the airintake means.

FIG. 10 is an end view of the shaker frame with the screen assembly inplace and showing the preferred retaining means for the screen assembly.

FIG. 11 is an enlarged fragmentary side elevation of the screen assemblybeing engaged with the retaining means.

'FIG. 12 is a partially sectioned end view of the shaker frame showingthe screen retaining latches and reduced in scale from FIGS. 10 and 11.

FIG. 13 is an isometric view of one of the latches enlarged wtih respectto the other drawings.

FIG. 14 is an underside view of the preferred embodiment of the screenassembly.

In the drawings like characters of reference indicate correspondingparts in the different figures.

Proceeding therefore to describe the invention in detail, referencecharacter 10 illustrates generally the supporting framework andenclosing casing of the machine including an upper side 11, sides 12,base 13, and end walls 14.

A source of air shown schematically by fan 15 connects to a dischargeconduit 16 which extends through the upper side 11 to the interior ofthe machine.

Material to be cleaned is fed through intake hopper 17 also situated onthe upper side 11, said hopper extending through the upper side to theinterior of the machine as will hereinafter be described.

Within the enclosure, is a base frame work 18 which includes a source ofpower 19 in the form of an electric motor, connected by means of chain20 to a double sprocket 21 mounted within bearings 22 also supportedupon the base framework 18. A further chain 23 extends from doublesprocket 21, to a further sprocket 22' mounted upon a shaft 23' whichalso includes an off center weight 24 to provide reciprocating vibrationto the device. This shaft 23 is mounted between hangers 25 dependingfrom a substantially rectangular shaker frame 26. This shaker frame isprovided with brackets 27 and spring leaves 28 extend from the bracketsdownwardly to the base frame 18 thus mounting the shaker frame for thevibrating reciprocating motion imparted by the rotatable off centerweight 24.

This shaker frame is substantially in the form of a channel 27' havingan upper flange 28 and a lower flange 29. Details of this are shown inFIG. 4 and it will be observed that the upper flange 28 is provided witha resilient strip 30 secured to the underside thereof and it should beunderstood that this resilient strip extends clear around theperimetrical shaker frame 26.

Extending upwardly from the shaker frame channel 27' is a perimetricalvertical flange 31 having a further flanged portion 32 interlockedtherewith as shown at 33. Also interlocked with the upper end of thisportion 32 is the lower end 34 of a flexible resilient web 35, theconnection being shown exploded for clarity as at 36 in FIG. 4. This webis preferably made of rubber or synthetic material.

The upper end 38 of the web 35 is also interlocked into a similarvertically extending flange portion 39 which in turn is locked to aperimetrical member 40 secured to the upper end 41 of the stationaryframework of the machine. The flanges 31, 32, 39 and the web 35 enclosethe space between the perimetrical member 40 and a shaker screenassembly 37 contained in the shaker frame 26, so that air may be drawnupwardly through the shaker screen assembly by action of the fan 15.

It will be seen that the offset weight 24 will cause the frame 27 tovibrate longitudinally upon the leaf spring members 28' and being heldby the flexible web 35, it being understood that this web is slightlypretensioned when the device is assembled and is held in this position,of course, by the location of the brackets 27 upon the leaf springs 28'.

The shaker screen assembly 37 is provided with side edges 42, lower edge43, and inwardly inclining upper edges 44 and the screen assembly alsoincludes an upper end portion 45 which is hinged transversely to theedges 44 along the line 46 shown in FIG. 7.

The perimetrical channel 27' of the shaker frame is also shapedsimilarly and the shaker screen assembly 37 is dimensioned to fit withinthe flange or channel forming the frame 27.

The shaker screen assembly 37 is normally held upwardly in sealingengagement with the resilient sealing strip 30 by means of plungerassemblies collectively designated 47 secured to the lower flange 29 ofthe frame 27. These plunger assemblies consist of cylinders 48 withinwhich plungers 49 engage, said plungers extending through apertureswithin the lower flange 29. The plungers are provided with stems 50 andsurrounded by compression springs 51 which react between the lower sides52 of the plungers and the base 53 of the cylinders so that the plungers49 are normally urged upwardly or biased upwardly in the direction ofarrow 54. The upper ends 55 of these plungers engage the underside ofthe screen assembly 37 and bias it upwardly into contact with thesealing strip 30 with suflicient pressure to completely seal the screenassembly into position within the frame and also to supply sufiicientfriction so that the vibration of the frame 27 is imparted equally tothe screen assembly 37.

When it is desired to remove the screen assembly 37 for replacementpurposes, the plungers 49 have to be drawn downwardly against pressureof springs 51 thus releasing the frame which can then be manipulatedfrom the frame 27, it being understood that the lower end 43 of thescreen assembly 37 terminates spaced from the lower end 56 of the frameto define a discharge area 57 for the material being cleaned as willhereinafter be described.

Secured to brackets 58 attached to the base framework 18, are wheels orpulleys 59 mounted on spindles 60. Cables 61 extend from extensions ofstems 50 of the plungers 49 and are connected to the perimeters of thesewheels or pulleys 59. A cable 62 may interconnect adjacent pulleys sothat rotation of one pulley by any conventional means will tighten allfour cables at the same time thus withdrawing plungers 49 from contactwith the underside of the screen assembly 37 and releasing same to theposition shown in FIG. 4.

Conversely, release of the cables 61 will enable the 4 compressionsprings 51 to urge the plungers upwardly as hereinbefore described.

The screen assembly 37 consists of a honeycomb core portion 63 definingcells 64, said core portion being formed from aluminium, paper orplastic as desired.

A relatively fine meshed screen panel 65 is adhesively secured to theupper side 66 of the honeycomb core portion 63 which supports thematerial being cleaned and allows air to flow therethrough.

An apertured sheet 67 for controlling the air flow characteristicsthrough the honeycomb core, is adhesively secured to the lower side 68of the honeycomb core portion 63 and this sheet is provided withapertures 69 connecting with individual cells 64 of the honeycombportion. This lower sheet can take the form of perforated strips orsheets of paper or metal which can be supplied with various sizes ofapertures and in various patterns and can be adhesively removed andreplaced quite readily. It can be placed on the underside of thehoneycomb core portion in strips so that a fiow pattern can beestablished for maximum efiiciency depending upon the characteristicsdesired. In effect, there is created an infinitely variable air flowpattern as any individual cell 64 can be varied at will.

The aforementioned upper end 45 is hingedly connected along the line 46as hereinbefore described and FIG. 2 shows details of this hingeconnection, reference character 46 illustrating a conventional pianohinge extending across the line 46. The various portions 31 and 32 arecut at this point and are provided with overlapping sides as illustratedat 31 and 32 so that this entire upper end can be moved upwardly anddownwardly Without destroying the seal formed by the web 35.

The pretension in the web 35 normally pulls the upper end 45 upwardly tothe maximum position shown in FIG. 2. Means are provided to move thisend downwardly within limits until it is in complete alignment with theremaining portion of the screen assembly 37, said means taking the formof a screw-jack 70 rotatable by means of control wheel 71 on the upperpanel 11 of the enclosure. Rotation of this screw-jack moves block 72upwardly or downwardly upon the screw-jack 70. A

cable 73 extends from block 72, around a sheave 74, to

be connected to the end 45 as at 75 so that by moving the block 72upwardly on the jack 70, the end 45 is pulled downwardly against tensionof Web 35 so that the desired inclination control of the portion 45relative to the main portion 37, is obtained.

In operation, material to be cleaned is fed into the hopper 17 and isdischarged upon the upper side 65 of the screen assembly 37, adjacentthe hinge line 46. The material may be spread across the screen assemblyby means of a flanged deflector 76.

The screen is vibrated by means of the source of power 19 ashereinbefore described, and air is drawn upwardly through the honeycombscreen assembly 37 including the end portion 45, by means of the fanassembly 15, air entering through the grill 77 within :one end of theenclosure. By controlling the velocity of the air flow and the apertures69 within the underside of the screen assembly, the material upon thescreen assembly may be fluidized so that the contaminants of heavierspecific gravity are moved upwardly towards the hinge line 46. Adjacentthis hinge line, a contaminant zone is established and the upper end 45has to be adjusted in positive inclination so that contaminants moveover this throated discharge end 45 but material being cleaned does not.The theoretically perfect inclination creates the contaminant zone sothat when one more piece of contaminant is added, one is discharged overthe throated end 45 thus maintaining the contaminant zone which acts asa barrier for the cleaned material. The discharged contaminants areconveyed by trough 78 to exteriorly of the machine. Cleaned material isdischarged over the lower end 43 of the screen assembly, an upwardlyextending flange 79 restricting this discharge to ensure that allcontaminants are cleaned before the material is discharged.

It discharges over the end 43 and into a conveyor or trough 80 alsoextending exteriorly of the machine.

A viewing panel (not illustrated) may be provided within the upper sideof the enclosure so that the contaminant zone can be seen and the upperend 45 of the screen assembly adjusted for the optimum performance whilethe machine is operating.

FIGS. to 14 show the preferred embodiment of the device insofar as theretaining means for the screen assembly is concerned.

I have provided a pair of spaced and parallel rods or bars 81 spanningthe shaker frame side channels 27 and being secured to the lower flanges29 as by welding.

The underside of the shaker screen assembly 37 is provided with fourspaced and parallel longitudinally extending stiffener members 82 and83, members 82 being the outer pair and members 83 being the inner pairas clearly shown in FIG. 14. These are secured to the perimetrical frame84 surrounding the honeycomb core assembly of the screen assembly.

Adjacent the lower edge '43 of the shaker screen assembly I have securedwedge plate members 85 to the outer stiffeners 82 and towards thejunctions between the side edges 42 and the inclined edges 44 of theframe 84 I have provided a further pair of wedge plates 86 secured tothe inner pair of stiffeners 83.

All of these wedge plates are of similar configuration and one of theseis shown in FIG. 11 in side elevation. It consists of an inclinedramping surface 87 which is adapted to engage the bars or rods 81 whenthe shaker screen assembly is pushed into position.

As the shaker frame assembly is moved forwardly and upwardly within thechannels of the frame 27, the wedge :or inclined surfaces 87 rideupwardly on the rods 81 thus forcing the upper edges of the screenassembly in compression contact with the resilient strips 30 on theunderside of the upper flanges 28. When fully forward, the rods 81register below the horizontal lower surfaces 88 of the Wedge plates thusholding the screen assembly firmly in position and resiliently mountedwithin the frame 27.

A cross member 89 spans the rear of the frame 27 and is provided with apair of latches 90 which are swung downwardly into position to registeragainst the lower edge 43 of the screen assembly thus preventingvibration from moving the screen assembly out of engagement with rods81, inadvertently. These latches consist of pivot bearing end 91, stem92, and curved shoe portions 93, it being understood that the curvedshoe portions engage the lower edge 43 of the screen assembly.

This method of detachably retaining the screen assembly within theshaker frame is the preferred embodiment of the invention over themethod described and illustrated in FIGS. 4 and 5.

What is claimed to be the present invention is:

1. In an air flotation separator for separating a mixture of particleshaving different specific gravities, the combination of a reciprocableshaker screen assembly including a honeycomb screen component adapted tohave an air stream passing upwardly therethrough, said screen assemblyhaving an elongated substantially rectangular main body portion with alower end edge and also having a convergently-sided throat portionhinged on a transverse axis to the upper end of said main body portionfor raising and lowering adjustment relative thereto, means fordepositing a mixture of particles to be separated on the main bodyportion of said screen assembly, means for imparting vibratory motion tothe screen assembly, means for passing an air stream upwardly throughthe honeycomb screen component whereby the mixture of particles on thescreen assembly is fluidized so that particles of relatively lowerspecific gravity are discharged over said lower end edge and particlesof relatively higher specific gravity migrate into said throat portionof the screen assembly for discharge over the upper end edge of thethroat portion, said upper end edge of the throat portion being of asubstantially smaller transverse dimension than the transverse dimensionof said main body portion of the screen assembly so that the particlesof higher specific gravity are laterally funneled during their migrationthrough the throat portion and prior to their discharge over the upperend edge of the throat portion, means biasing said throat portion aboutits hinge axis to its raised position, and remotely actuated meansconnected to the throat portion for lowering the same against the biasof said last mentioned means.

2. The device as defined in claim 1 which also includes a supportingframework, a shaker frame mounted for reciprocating movement in saidframework, said shaker frame containing said shaker screen assembly, andmeans including a resilient flexible web enclosing the space in theframework above said shaker frame so that a stream of air may be drawnupwardly through said shaker screen assembly by said air passing means.

3. The device as defined in claim 2 which also includes a supportingframework, a reciprocable shaker frame mounted in said framework andcontaining said shaker screen assembly, said shaker frame including aperimetric flange and sealing means at the underside of said flange,said shaker screen assembly having its perimetric portion engageablewith said sealing means, and means biasing the shaker screen assemblyinto sealing engagement with the sealing means. a

4. The device as defined in claim 3 wherein said resilient flexible webis tensioned and constitutes said means for biasing said throat portionof the shaker screen assembly to its raised position.

5. The device as defined in claim 4 wherein said shaker screen assemblyalso includes a screen component covering the top of said honeycombcomponent, and an apertured sheet component at the underside of thehoneycomb component, the apertures in said sheet component communicatingwith cells of the honeycomb component.

6. The device as defined in claim 3 wherein said shaker screen assemblyalso includes a screen component covering the top of said honeycombcomponent, and an apertured sheet component at the underside of thehoneycomb component, the apertures in said sheet component communicatingwith cells of the honeycomb component.

7. The device as defined in claim 3 wherein said means biasing saidshaker screen assembly into engagement with said sealing means comprisea plurality of upwardly springloaded plungers mounted in said shakerframe and engaging the underside of the shaker screen assembly, andremotely actuated means connected to said plungers for retracting thesame downwardly to facilitate releasing of the screen assembly andremoval thereof from the shaker r frame.

8. The device as defined in claim 3 wherein said means biasing saidshaker screen assembly into engagement with said sealing means comprisea plurality of rods spanning said shaker frame, and a plurality of wedgeplates on the underside of the shaker screen assembly cooperating withsaid rods when the screen assembly is moved into operating position inthe shaker frame to bias the screen assembly upwardly.

9. The device as defined in claim 8 together with stiffeners extendinglongitudinally of said shaker screen assembly and having said wedgeplates secured thereto, and latch means for retaining the screenassembly in its operating position in said shaker frame.

10. The device as defined in claim 2 wherein said resilient flexible webis tensioned and constitutes said means for biasing said throat portionof the shaker screen assembly to its raised position.

11. The device as defined in claim 10 wherein said shaker screenassembly also includes a screen component covering the top of saidhoneycomb component, and an apertured sheet component at the undersideof the honeycomb component, the apertures in said sheet componentcommunicating with cells of the honeycomb component.

12. The device as defined in claim 1 which also includes a supportingframework, a reciprocable shaker frame mounted in said framework andcontaining said shaker screen assembly, said shaker frame including aperimetric flange and sealing means at the underside of said flange,said shaker screen assembly having its perimetric portion engageablewith said sealing means, and means biasing the shaker screen assemblyinto sealing engagement with the sealing means.

13. The device as defined in claim 12 wherein said shaker screenassembly also includes a screen component covering the top of saidhoneycomb component, and an apertured sheet component at the undersideof the honey- Comb component, the apertures in said sheet componentcommunicating with cells of the honeycomb component.

14. The device as defined in claim 13 wherein said means biasing saidshaker screen assembly into engagement with said sealing means comprisea plurality of upwardly spring-loaded plungers mounted in said shakerframe and engaging the underside of the shaker screen assembly, andremotely actuated means connected to said plungers for retracting thesame downwardly to facilitate releasing of the screen assembly andremoval thereof from the shaker frame.

15. The device as defined in claim 13 wherein said means biasing saidshaker screen assembly into engagement with said sealing means comprisea plurality of rods spanning said shaker frame, and a plurality of wedgeplates on the underside of the shaker screen assembly cooperating withsaid rods when the screen assembly is moved into operating position inthe shaker frame to bias the screen assembly upwardly.

16. The device as defined in claim 15 together with stiffeners extendinglongitudinally of said shaker screen assembly and having said wedgeplates secured thereto,

and latch means for retaining the screen assembly in its operatingposition in said shaker frame.

17. The device 'as defined in claim 12 wherein said means biasing saidshaker screen assembly into engagement with said sealing means comprisea plurality of upwardly spring-loaded plungers mounted in said shakerframe and engaging the underside of the shaker screen assembly, andremotely actuated means connected to said plungers for retracting thesame downwardly to facilitate releasing of the screen assembly andremoval thereof from the shaker frame.

18. The device as defined in claim 1 wherein said shaker screen assemblyalso includes a screen component covering the top of said honeycombcomponent, and an apertured sheet component at the underside of thehoneycomb component, the apertures in said sheet component communicatingwith cells of the honeycomb component.

19. The device as defined in claim 2 wherein said shaker screen assemblyalso includes a screen component covering the top of said honeycombcomponent, and an apertured sheet component at the underside of thehoneycomb component, the apertures in said sheet component communicatingwith cells of the honeycomb component.

References Cited UNITED STATES PATENTS 1,941,490 1/1934 Peale 2094692,348,344 5/1944 Holmes 209-467 2,404,414 7/1946 Sutton 209-4672,764,293 9/ 6 Forsberg 209467 FRANK W. LUTTER, Primary Examiner R.HALPER, Assistant Examiner US. Cl. X.R.

